Solid state structure-property behavior of semicrystalline poly(ether-block-amide) PEBAX® thermoplastic elastomers

The solid state structure-property behavior was investigated of a series of poly(ether-block-amide) PEBAX(R) thermoplastic elastomers based on nylon 12 and poly(tetramethylene oxide) with varying hard segment content. Particular emphasis was placed on better defining the morphological features of this entire series of commercially available materials. Compression molded and solution cast samples were studied by the techniques of DMA, DSC, WAXS, SAXS, AFM, SALS and stress-strain response. The strain-induced crystallization behavior of the soft polyether (PE) segments was also investigated. All samples exhibited a microphase separated morphology over a broad temperature range. As expected, an increase in the interconnectivity of the polyamide hard phase was greatly controlled by the polyamide (PA) content. Due to the crystallization of the PA hard segment, the formation of PA lamellar crystals was noted in both melt and solution cast films. At the higher PA contents, a distinct spherulitic superstructure was also observed but this form of morphological texture was diminished as the PE soft segment content increased. Limited studies of the deformation/recovery behavior of the spherulitic superstructure provided further information concerning the interaction between the hard and soft segments. (C) 2002 Elsevier Science Ltd. All rights reserved.